It is amusing that in 2005, "VLDB" (precursor term to "big data") was defined in Wikipedia to be "larger than 1TB".. after reading through the post and the author's experience.. it would appear that this was not actually a completely terrible estimate, although there are larger and smaller: https://en.wikipedia.org/w/index.php?title=Very_large_databa...

The current version of that article states: "There is no absolute amount of data that can be cited. For example, one cannot say that any database with more than 1 TB of data is considered a VLDB. This absolute amount of data has varied over time as computer processing, storage and backup methods have become better able to handle larger amounts of data.[5] That said, VLDB issues may start to appear when 1 TB is approached,[8][9] and are more than likely to have appeared as 30 TB or so is exceeded.[10]" https://en.wikipedia.org/wiki/Very_large_database